One type of conventional rifle range backstop known as an escalator backstop has a general configuration in the shape of sideways "V." The design of the trap causes the bullets to be directed to the apex of the "V" and fall into a trap at the rear of the backstop. The "Indoor Range Design Criteria" published by the National Rifle Association sets forth the general requirements for an escalator type backstop at .paragraph. 3.01.06(2). Typical escalator trap designs use a series of overlapped plates to form a deflecting surface, with the direction of overlap being chosen so that a flat edge is never exposed in the direction facing the shooter.
Another conventional type of backstop is the angled plate and trap, which is similar to the escalator trap in its general shape, but uses flat plates and deflects the projectiles into a sand or water trap. For example, U.S. Pat. No. 3,982,761 --DeVogelaere, discloses a backstop designed for air guns and pellet guns. The backstop plate is designed so that the energy of the pellet is absorbed and the pellet drops into a trap area at the rear of the structure.
One aspect of the design of backstops and bullet traps generally is the removal of the spent projectiles, which are typically lead or lead alloy bullets or pellets. Lead is a hazardous substance, and for this reason alone should not be permitted to accumulate inside the structure of a shooting range. Additionally, it is necessary to clean out accumulated spent projectiles for reasons of shooting safety and to ensure proper operation of the backstop, bullet trap, and associated equipment such as target hangers and the like.
Thus, in the prior art, a hinged door or some other type of removable section or clean out port was provided at the rear of a backstop. Typically, a crawl space or other rear area access was provided between the backstop and the wall to permit the removable section to be opened, thus permitting the spent bullets in the trap to be collected.
For example, U.S. Pat. No. 4,509,301 to Head discloses a modular shooting range that includes a bullet trap that uses an angle plate-type design. The bullet trap is provided with a clean out door that is beneath the rear section of the backstop, just ahead of a water-filled bullet trap. U.S. Pat. Nos. 5,070,763 and 5,121,671, both to Coburn, disclose an angle plate bullet trap that is connected to a spiral chamber where bullets dissipate energy before falling into a water-filled collecting vessel. The trap is designed so that the fired bullets can be retrieved and examined. A clean out door is provided along the side of the spiral chamber, near the rear of the device.
If a number of either of the prior art designs are installed in an indoor setting adjacent to one another, provision would have to be made either for a rear access or side access area. However, because space is at a premium in indoor shooting ranges, it is desirable to place the rear of the backstop against a wall, permitting the longest possible range distance, and to place adjacent targets and backstops as close to one another as feasible to maximize the number of shooters who can use the range at one time. These considerations are of course contrary to the requirements described above that relate to providing access for cleaning out the spent projectiles.
It would therefore be desirable to provide a backstop and bullet trap design that maximizes available interior space by permitting the backstop to be placed adjacent a rear wall, while also permitting backstops to be placed adjacent one another. It is also desirable to provide access to a bullet trap so that the spent projectiles can be collected on a regular basis. It is therefore an object of the present invention to provide a backstop design wherein access to spent projectiles from the rear or side of the backstop is not required.